The Chinese lasers were used to "dazzle" optical cameras on US spy sats, not affect the GPS sats. Spy sats are in particularly low orbit as well. Close up sats need smaller zoom lenses to see the bad guys.
Death Valley is only 282 feet below see level at its lowest point. You get a normal (high) amount of sun for the weather (normally no clouds) and latitude.
The reason Death Valley is a bad place to build a solar plant is because if the generation is thermal, there is no cooling water. For photovoltaics, their output drops somewhat with temperature and Death Valley isn't particularly close to a large population center so transmission losses are significant. Why not put those same panels on roofs in SoCal?
It is much more likely that the first tether used to raise payload to orbit will be rotating in a LEO orbit. A hypersonic airplane (or gas cannon for high G tolerant payloads) would lift the payload to high altitudes where it rendezvouses with one end of the tether. This "two stage" to orbit version of the space elevator drastically cuts the engineering requirements of the tether. For a surface to GEO tether we can only speculate about near perfect weaves of carbon nanotubes. With a high altitude rotovator you can use Spectra or Spectra-like polymer cables.
In this case the power beaming would probably come from the counterweight on the opposite end of the tether. The relative position of the payload climber and the beaming station wouldn't change that much but the whole tether system would be rotating relative to the earth. I doubt the beam would be much trouble on the surface of the earth but it might make sense for the beaming system to defocus by the time it reaches earth - IE don't make it a coherent, low divergence laser.
This also means that the energy for the beam has to get to the counterweight somehow. A ballistic launch system like a gas gun would be very helpful in that respect. Most fuels don't might a few hundred Gs, especially not fissionables. A space elevator would be much more convenient but unfortunately we are on a 1g (9.8 m/s^2) planet. If our rock was smaller/less massive it would be much easier!
We are are swimming in natural gas in the US due to new extraction technology. Gas power plants are cheap, small and clean (no particulates or hydrocarbons and 50% of the CO2 as coal). Pickens is huge in natural gas and always promoted a partnership of gas and wind. So this is just like before, except now that gas is cheap... skip the wind part.
"For powered aviation, the course of a round-the-world record must start and finish at the same point and cross all meridians; the course must be at least 36,787.559 kilometres (22,858.729 mi) long (which is the length of the Tropic of Cancer). The course must include set control points at latitudes outside the Arctic and Antarctic circles.[3]"
And you can circumnavigate the globe much easier as well. Technically you could just take a tight diameter (say one mile) spin directly around the North pole and qualify on a technicality.
While not stated explicitly, I think the idea is to fly 24.8k miles in one direction and come back to where you started. That could be pole to other pole and back or around the equator or something in between. In any case you have to be traveling faster than the speed of sound to do it the honest way with the sun overhead at all times.
There is an analogy there in the macro physics but that doesn't mean the small scale stuff like QM will be mirrored.
You can model gravity in the orbital mechanics sense with a marble and vertical cone that tapers at 1/square(height). That doesn't mean it will do anything relativistic or quantum mechanical.
The raster image of a photo makes it easier to detect a derivative work. A good example of this is the controversy over the Obama poster versus a particular Time photo of the President in the same pose.
Clip art is a bit tricker since it is vector based. If someone ends up with a similar design is it tough to prove whether it is a derivative work or an independent rendition of the same public domain thing/image.
Clip art of a generic bicycle developed independently can't be sued for copyright infringement by Riddick because it bears a resemblance to his version. They are both representing a bike, something that you can't copyright. Of course two doodles of the same thing will look similar.
Actually this was a border search. The agents already had every search power that a warrant can convey. You can't waive rights that you don't have and at the borders you have no fourth amendment rights. Even if you had fourth amendment rights, the context was coercive. If there was any consent if was that of following the commands of a border agent executing his search powers, not a consent to a voluntary search.
The scope of discovery should be confined only to what the agents actually saw at the time of the search and nothing else.
The rules of discovery are far more generous to the cops than you seem to think. All they need is probable cause. They have it and they now have a warrant from a judge. From a fourth amendment perspective it's a strong position.
So are they compelling the defendent to turn over the key to a locked safe through a valid warrant, or are they compelling him to provide incriminating evidence, especially incriminating evidence that was not previously given?
I think the answer is kind of both.
Many defendants invoke the fifth amendment to prevent providing information that would naturally lead to incriminating evidence. Can the government compel a suspect to reveal his Swiss bank account number to help prove a crime? I don't think so, even if there is circumstantial evidence that such an account exists.
Except that you do not have a fourth amendment right in a border search, so there was no consent.
The fourth amendment right does not have to be explicitly waived by the suspect if the search is not coerced. The police can just ask to search your stuff, and if they asked nicely, the search is valid. It is valid even if they failed to tell you that you could refuse the search, what they are looking for or what crime they suspect you of.
But in the context of a border search, the defendant had no fourth amendment protection at all, so he could not waive it and I would argue that the context of the search is implicitly coercive.
In any case the defendant should only be compelled to provide precisely the same information that the border guard testified he witnessed. The rest of the data should be off limits. He didn't show the agent the rest of the drive or open certain very suspiciously named files for viewing, so he hasn't waived his fifth amendment rights to that unseen information.
Certainly there is circumstantial evidence already that the guy is a total sicko and I hope his password was a lousy one that will be broken quickly. That way I can feel better about a SCOTUS decision that protects him from having to give over the password - which I think is the right decision.
I think the judge was interpreting the password like a key to a physical door. The defendant agreed to a police search and is now required to allow them to complete that search, including the "locked back room" to use a physical analogy.
Here is the text of the fourth amendment:
"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."
Notice that "papers" are mentioned and therefore even the 200+ year old constitution appreciated privacy of information.
Because the defendant gave permission for the search, his fourth amendment argument is weak, but waiving his rights in one context, his fourth amendment rights, does not waive his fifth amendment rights. Also weakening a fourth amendment argument is that if this was a border search, he had no fourth amendment right against search.
But again, that doesn't mean anything in the context of the fifth amendment however. The defendant should just refuse to give the password, invoke his fifth amendment right and then fight the contempt charge where he has a great case IMHO.
Electric motors are also much more powerful per kilo than piston engines and use a much simpler transmission. High voltage electric motors, the type that a 3500V supercap could power, would be even lighter than the 375V motor used in the Tesla roadster or other typical traction duty.
You need to look at the whole power train, from engine to axle.
Yes, because oil can be refined into a liquid fuel well adapted to combustion in an internal combustion engine. Coal, being a solid fuel, was used to fire a boiler that ran a steam engine, or an external combustion engine. Internal combustion had more power density, was more fuel efficent and more reliable. Boiler explosions are not fun at all! That is why oil won out back then.
These days steam can be efficent but no one really bothers with coal. It is still dirty and has the fuel handling problems associated with all solid fuels.
I totally agree that it wouldn't count in an academic sense - IE achieving realtime subsurface scattering.
I just meant rendering human figures that don't look like they are made out of plastic. Maybe on close inspection or in rare circumstances the trick becomes apparent but in practical terms the effect works. Sometimes that's the best you can do and it is better than nothing. I am think of some of the texture swapping that used to be done before shader programs. Didn't Quake do something like that to implement lighting effects? I seem sto recall a color pallet limitation.
I guess the latest Id engine shows that there are no particular limits to raster as you suggest as long as the optical effect can be pushed through a shader.
It is certainly the case that 3d gaming environments are typically static, and except for bleeding edge gaming engines, they have to be.
If rendering isn't the reason for static game worlds, why aren't there more?
I see your point and the point of fluffykitty. I guess my intuition is that the tricks are piled on so thick in your typical raster based FPS engine that in order to simulate lighting, reflections and transparency effects certain things, like the environment, need to remain static.
Raytracing addresses some of these shortcomings of raster so that these tricks need not be used, a more ground up approach. That way the environment can be more dynamic as its features are recalculated in real time.
At least in the beginning I imagine skin features like you descibe would be pre-rendered into the texture as some sort of efficiency compromise. It's not like raster methods do a great job right now anyway. Most games are still going further into uncanny valley rather than climbing out of it.
The gameplay improvement is in deformable physical environments. Combined with mainstream physics engines, raytracing would allow for a sea-change in gameplay by allowing interactive gaming environments.
Raster methods rely on a bunch of tricks, many of which need to be precalculated for static maps. The most obvious example is binary space partioning tables. This leads to very static feeling environments that disallow interaction beyond doors of various types and moving platforms.
24fps film works because the movie camera exposed the film for a large fraction of the 1/24 sec period. The action from that window is blurred onto one frame. This naturally happens on the human retina naturally and so when we view these blurred frames our brains can make sense of them without much fatigue at all. It seems like a much faster frame rate.
You'll notice in movies that the director will switch to high speed film. The openning scene of "Saving Private Ryan" is a well known example. It looks choppy. You can see individual specks of dirt being blown past the camera by the explosions. That's because the faster film allows the movie camera to hold the shutter open for a much shorter period. That means the "action" is caught for a much shorter part of the 1/24 second window. The shutter is faster but the film is still only 24fps. That means more detail and less bluring - so little bluring in fact that it looks choppy.
The supporting analog circuitry (caps, inductors, etc...) is much smaller and cheaper when switching frequency is increased. I'd be shocked if those car lights were running under 1kHz. Perhaps two similiar frequencies were being used and you were seeing a beating effect? Most likely it came from a facetted reflector with imperfect coverage strobing you with light and dark spots in the light cone.
Shielding helps with those losses, as does properly terminating the wire at a wavelength node. Also keep in mind that the distribution system could keep track of usage and only power those lines that need power. I agree that 400 Hz is a good compromise and at ~7x the frequency of 60hz, the transformers can be 7x smaller. Dropping the voltage to 48 reduces the transistor needs even more without too much . It's doable.
The thin aluminum shrouds they are using would not stop any small arms. HUMVEEs need extra armor just to stop AK rounds and they are made of steel and designed to roll, not fly. The article suggests that the vehicle is quieter than one with exposed rotors which is helpful. I imagine it also has to do with safety. No one wants a programming error to turn a UAV into a troop blender.
It seems to me like a GPS steerable parachute drop from a C-130 would be a better use of resources. The C-130 can carry a lot more cargo and is more efficent with fuel per pound. The plane itself could be used as a flying warehouse. I believe those rectangular paragliding chutes have a glide ratio of 5 to 1, so a C-130 flying at 10km could deliver a payload from 50km away.
Wall warts are big and heavy because they contain a big, heavy transformer. Transformers change AC voltages around - higher or lower. The bigger the change in voltage, the bigger the transformer needs to be, for the same frequency. Changing 120 volts to 5 volts is a large change - a 96% reduction in voltage to be exact. So if the starting voltage was lower, the wall would be smaller and lighter. Great! go low voltage... except that low voltages have big line losses because the currents are big.
The solution? Higher frequencies! 50/60 herts is SUPER low frequency. It's so low frequency it is hard to do anything with. In fact the first step of the new, light switching power supplies is to chop the 60hz signal into a 30khz+ signal that can be run through a tiny efficient transformer.
We should distribute 48 volt @ 20khz through a shielded cable in the home. 48 volts is high enough for low line losses (120 volts works too though) and the higher frequency makes the voltage converters light and efficient.
Slashdot Mirror
The Chinese lasers were used to "dazzle" optical cameras on US spy sats, not affect the GPS sats. Spy sats are in particularly low orbit as well. Close up sats need smaller zoom lenses to see the bad guys.
Death Valley is only 282 feet below see level at its lowest point. You get a normal (high) amount of sun for the weather (normally no clouds) and latitude.
The reason Death Valley is a bad place to build a solar plant is because if the generation is thermal, there is no cooling water. For photovoltaics, their output drops somewhat with temperature and Death Valley isn't particularly close to a large population center so transmission losses are significant. Why not put those same panels on roofs in SoCal?
It is much more likely that the first tether used to raise payload to orbit will be rotating in a LEO orbit. A hypersonic airplane (or gas cannon for high G tolerant payloads) would lift the payload to high altitudes where it rendezvouses with one end of the tether. This "two stage" to orbit version of the space elevator drastically cuts the engineering requirements of the tether. For a surface to GEO tether we can only speculate about near perfect weaves of carbon nanotubes. With a high altitude rotovator you can use Spectra or Spectra-like polymer cables.
In this case the power beaming would probably come from the counterweight on the opposite end of the tether. The relative position of the payload climber and the beaming station wouldn't change that much but the whole tether system would be rotating relative to the earth. I doubt the beam would be much trouble on the surface of the earth but it might make sense for the beaming system to defocus by the time it reaches earth - IE don't make it a coherent, low divergence laser.
This also means that the energy for the beam has to get to the counterweight somehow. A ballistic launch system like a gas gun would be very helpful in that respect. Most fuels don't might a few hundred Gs, especially not fissionables. A space elevator would be much more convenient but unfortunately we are on a 1g (9.8 m/s^2) planet. If our rock was smaller/less massive it would be much easier!
We are are swimming in natural gas in the US due to new extraction technology. Gas power plants are cheap, small and clean (no particulates or hydrocarbons and 50% of the CO2 as coal). Pickens is huge in natural gas and always promoted a partnership of gas and wind. So this is just like before, except now that gas is cheap... skip the wind part.
Ok if 89.9 degrees latitude does not count what is the maximum? As always, wiki has an answer:
http://en.wikipedia.org/wiki/Circumnavigation#Aviation
"For powered aviation, the course of a round-the-world record must start and finish at the same point and cross all meridians; the course must be at least 36,787.559 kilometres (22,858.729 mi) long (which is the length of the Tropic of Cancer). The course must include set control points at latitudes outside the Arctic and Antarctic circles.[3]"
So there you go.
And you can circumnavigate the globe much easier as well. Technically you could just take a tight diameter (say one mile) spin directly around the North pole and qualify on a technicality.
While not stated explicitly, I think the idea is to fly 24.8k miles in one direction and come back to where you started. That could be pole to other pole and back or around the equator or something in between. In any case you have to be traveling faster than the speed of sound to do it the honest way with the sun overhead at all times.
The earth is 24.8k miles in circumference, so you need to fly about 1,030 miles per hour to stay under the sun at all times.
Good luck getting a solar-powered electric prop plane to fly just under mach two.
There is an analogy there in the macro physics but that doesn't mean the small scale stuff like QM will be mirrored.
You can model gravity in the orbital mechanics sense with a marble and vertical cone that tapers at 1/square(height). That doesn't mean it will do anything relativistic or quantum mechanical.
The raster image of a photo makes it easier to detect a derivative work. A good example of this is the controversy over the Obama poster versus a particular Time photo of the President in the same pose.
Clip art is a bit tricker since it is vector based. If someone ends up with a similar design is it tough to prove whether it is a derivative work or an independent rendition of the same public domain thing/image.
Clip art of a generic bicycle developed independently can't be sued for copyright infringement by Riddick because it bears a resemblance to his version. They are both representing a bike, something that you can't copyright. Of course two doodles of the same thing will look similar.
Actually this was a border search. The agents already had every search power that a warrant can convey. You can't waive rights that you don't have and at the borders you have no fourth amendment rights. Even if you had fourth amendment rights, the context was coercive. If there was any consent if was that of following the commands of a border agent executing his search powers, not a consent to a voluntary search.
The scope of discovery should be confined only to what the agents actually saw at the time of the search and nothing else.
The rules of discovery are far more generous to the cops than you seem to think. All they need is probable cause. They have it and they now have a warrant from a judge. From a fourth amendment perspective it's a strong position.
So are they compelling the defendent to turn over the key to a locked safe through a valid warrant, or are they compelling him to provide incriminating evidence, especially incriminating evidence that was not previously given?
I think the answer is kind of both.
Many defendants invoke the fifth amendment to prevent providing information that would naturally lead to incriminating evidence. Can the government compel a suspect to reveal his Swiss bank account number to help prove a crime? I don't think so, even if there is circumstantial evidence that such an account exists.
Except that you do not have a fourth amendment right in a border search, so there was no consent.
The fourth amendment right does not have to be explicitly waived by the suspect if the search is not coerced. The police can just ask to search your stuff, and if they asked nicely, the search is valid. It is valid even if they failed to tell you that you could refuse the search, what they are looking for or what crime they suspect you of.
But in the context of a border search, the defendant had no fourth amendment protection at all, so he could not waive it and I would argue that the context of the search is implicitly coercive.
In any case the defendant should only be compelled to provide precisely the same information that the border guard testified he witnessed. The rest of the data should be off limits. He didn't show the agent the rest of the drive or open certain very suspiciously named files for viewing, so he hasn't waived his fifth amendment rights to that unseen information.
Certainly there is circumstantial evidence already that the guy is a total sicko and I hope his password was a lousy one that will be broken quickly. That way I can feel better about a SCOTUS decision that protects him from having to give over the password - which I think is the right decision.
I think the judge was interpreting the password like a key to a physical door. The defendant agreed to a police search and is now required to allow them to complete that search, including the "locked back room" to use a physical analogy.
Here is the text of the fourth amendment:
"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."
Notice that "papers" are mentioned and therefore even the 200+ year old constitution appreciated privacy of information.
Because the defendant gave permission for the search, his fourth amendment argument is weak, but waiving his rights in one context, his fourth amendment rights, does not waive his fifth amendment rights. Also weakening a fourth amendment argument is that if this was a border search, he had no fourth amendment right against search.
But again, that doesn't mean anything in the context of the fifth amendment however. The defendant should just refuse to give the password, invoke his fifth amendment right and then fight the contempt charge where he has a great case IMHO.
Electric motors are also much more powerful per kilo than piston engines and use a much simpler transmission. High voltage electric motors, the type that a 3500V supercap could power, would be even lighter than the 375V motor used in the Tesla roadster or other typical traction duty.
You need to look at the whole power train, from engine to axle.
Yes, because oil can be refined into a liquid fuel well adapted to combustion in an internal combustion engine. Coal, being a solid fuel, was used to fire a boiler that ran a steam engine, or an external combustion engine. Internal combustion had more power density, was more fuel efficent and more reliable. Boiler explosions are not fun at all! That is why oil won out back then.
These days steam can be efficent but no one really bothers with coal. It is still dirty and has the fuel handling problems associated with all solid fuels.
I totally agree that it wouldn't count in an academic sense - IE achieving realtime subsurface scattering.
I just meant rendering human figures that don't look like they are made out of plastic. Maybe on close inspection or in rare circumstances the trick becomes apparent but in practical terms the effect works. Sometimes that's the best you can do and it is better than nothing. I am think of some of the texture swapping that used to be done before shader programs. Didn't Quake do something like that to implement lighting effects? I seem sto recall a color pallet limitation.
I guess the latest Id engine shows that there are no particular limits to raster as you suggest as long as the optical effect can be pushed through a shader.
It is certainly the case that 3d gaming environments are typically static, and except for bleeding edge gaming engines, they have to be.
If rendering isn't the reason for static game worlds, why aren't there more?
I see your point and the point of fluffykitty. I guess my intuition is that the tricks are piled on so thick in your typical raster based FPS engine that in order to simulate lighting, reflections and transparency effects certain things, like the environment, need to remain static.
Raytracing addresses some of these shortcomings of raster so that these tricks need not be used, a more ground up approach. That way the environment can be more dynamic as its features are recalculated in real time.
At least in the beginning I imagine skin features like you descibe would be pre-rendered into the texture as some sort of efficiency compromise. It's not like raster methods do a great job right now anyway. Most games are still going further into uncanny valley rather than climbing out of it.
The gameplay improvement is in deformable physical environments. Combined with mainstream physics engines, raytracing would allow for a sea-change in gameplay by allowing interactive gaming environments.
Raster methods rely on a bunch of tricks, many of which need to be precalculated for static maps. The most obvious example is binary space partioning tables. This leads to very static feeling environments that disallow interaction beyond doors of various types and moving platforms.
24fps film works because the movie camera exposed the film for a large fraction of the 1/24 sec period. The action from that window is blurred onto one frame. This naturally happens on the human retina naturally and so when we view these blurred frames our brains can make sense of them without much fatigue at all. It seems like a much faster frame rate.
You'll notice in movies that the director will switch to high speed film. The openning scene of "Saving Private Ryan" is a well known example. It looks choppy. You can see individual specks of dirt being blown past the camera by the explosions. That's because the faster film allows the movie camera to hold the shutter open for a much shorter period. That means the "action" is caught for a much shorter part of the 1/24 second window. The shutter is faster but the film is still only 24fps. That means more detail and less bluring - so little bluring in fact that it looks choppy.
The supporting analog circuitry (caps, inductors, etc...) is much smaller and cheaper when switching frequency is increased. I'd be shocked if those car lights were running under 1kHz. Perhaps two similiar frequencies were being used and you were seeing a beating effect? Most likely it came from a facetted reflector with imperfect coverage strobing you with light and dark spots in the light cone.
Shielding helps with those losses, as does properly terminating the wire at a wavelength node. Also keep in mind that the distribution system could keep track of usage and only power those lines that need power. I agree that 400 Hz is a good compromise and at ~7x the frequency of 60hz, the transformers can be 7x smaller. Dropping the voltage to 48 reduces the transistor needs even more without too much . It's doable.
The thin aluminum shrouds they are using would not stop any small arms. HUMVEEs need extra armor just to stop AK rounds and they are made of steel and designed to roll, not fly. The article suggests that the vehicle is quieter than one with exposed rotors which is helpful. I imagine it also has to do with safety. No one wants a programming error to turn a UAV into a troop blender.
It seems to me like a GPS steerable parachute drop from a C-130 would be a better use of resources. The C-130 can carry a lot more cargo and is more efficent with fuel per pound. The plane itself could be used as a flying warehouse. I believe those rectangular paragliding chutes have a glide ratio of 5 to 1, so a C-130 flying at 10km could deliver a payload from 50km away.
Wall warts are big and heavy because they contain a big, heavy transformer. Transformers change AC voltages around - higher or lower. The bigger the change in voltage, the bigger the transformer needs to be, for the same frequency. Changing 120 volts to 5 volts is a large change - a 96% reduction in voltage to be exact. So if the starting voltage was lower, the wall would be smaller and lighter. Great! go low voltage... except that low voltages have big line losses because the currents are big.
The solution? Higher frequencies! 50/60 herts is SUPER low frequency. It's so low frequency it is hard to do anything with. In fact the first step of the new, light switching power supplies is to chop the 60hz signal into a 30khz+ signal that can be run through a tiny efficient transformer.
We should distribute 48 volt @ 20khz through a shielded cable in the home. 48 volts is high enough for low line losses (120 volts works too though) and the higher frequency makes the voltage converters light and efficient.